Ceiling



Oct. 10, 1933. L. NAVRATIL 1,930,251

CEILING Filed DBG. 24, 1930 2 Sheets-Sheet l 5 /lllllLr//l//llll 'Irl/[111111 l /lIllll/lllll I..

Patented Oct. 10, 1933 I UNIT En STATES f CEILING Ladislaus Navratil, Budapest, Hungary Application December 2'4, 1930, serial No.

504,554, and in HungaryDecember 31,1929

4 Claims.

Ferro-concreteceilings are known which comprise essentially: parallel Aterror-concrete carriers for-ming beams supported' byy the main. walls of the building, with hollow bodiesbuilt` in between 5.6 the carriers, thesey bodies lling in the spaces between the carriers and" being also adaptedl to formthe iinishedl face of the ceiling and the frame therefor, solthat the conventional wooden backing may be dispensed. with.

With ceilings of this type the hollow filling bodieslarefgenerally oftheshape of railway rails having a head and. a broad flat-base, presenting longitudinal channelsand made of baked clay, andf in constructing the ceiling they are laid in rows, at right angles tothe main Walls, on a flat horizontal'y wooden frame with the edges ofthe base flanges touching; thus the openy topped channels` are formedbetween the several rows,

theseV channels kforming moulds, for. the ferro- 'concrete carriersand the ceiling. The carriers are produced by. filling concrete intoy theV chan-- nels and tamping it down in conventional manriers, while the flangesat thebaselof the hollow bodies extend laterally underneath thev carriers Y Lr up totheir centralil'ongitudinal planes, thuscompletely,l cover-ing' the undersides of: 'the' carriers.

Thisrform of' ceiling is satisfactory-.asiat as it offers a smooth, flat: face-*free oircrackszand flaws, and it isi-an improvement on,A other forms of ferro-concrete ceilingsnas'regards sound and heat insulating properties, anditis shallow, but it hasthe disadvantage that it involves comparatively v-erysmall distances between; the carriers, by, reasonV ci" the hollowr bodies being ofi very limited width, so that theseceilings require the use r of too many carriers which notY onlymake the ceiling very difficult.' to constructbutalsoincrease' its weight and: cost'. of production to an appreciable extent. The reason for. thisisthat centime-ters, which, having regard tothe fact that the flanged bases must. reachup tothe centrallongitudinali planes off the carriers, reduces.

-the distance between the carriers to. 30`centimetersin the finishedfE ceiling.

Theobject ofthe present inventionis to providefaferroconcrete hollow. ceiling of this kind'. with; hollow bodies; andi carriers therefory in,

551 which` notaonly theabove-.mentioned serious the technical diiliculties of constructionprevent' the hollow bodies being made wider than 30v disadvantage obviated, but it also enablesA the distance between the carriers to be doubled' at least, but the particular construction of the carriers and hollow bodies increases thei static' safety and strength of the ceiling. This also results in 00 the weight as well as the cost of. productionsof the ceiling being considerably reduced, without affecting the above mentioned advantages" ci,- such a ceiling.

In the construction of ceiling according tov thel 05 invention at least two hollow bodies are arranged side by side between each two adjacent ferro;- concretecarriers, at rightangles'tothe. run ofthe latter andlling the spaces-between saidrcavriers..

These hollow bodies are preferably arrangedawibhL 70y their longitudinal axes in parallel' to the carriers, and they rest in a vault like manner withtheir outer longitudinal sides against the abutmentlike inclined faces of the carriers.` This inclina-f tion-of the' side faces of. thecarriers, together fwlthl 'I6` the correspondingly inclined formation of. adjoining side facesofthehollow bodies, isl an important feature, for the reason thatthet msultant pressure of the hollow'bodiesI subjects` the carriers to a favourable strain, namely oom-r 90' pression, whereas in the case of known ceilings of this type,fwhere only one hollow bodyoccuples'" the space between each pair.l of carriers, thehol low bodies are only suspendedat their heads from the rib-like enlargement of the lower endsl'offthe. 85* carriers, so that the latter are subjected tof .unfavourable stressjnamely tension, in the direction of their height. These hollow bodies ac'- cording to the invention are in the form ofleft`` and right hand side separately unsymmet'ri'calf 90 bodies, but collectively provide a single sym-- metrical body which forms a self-supporting flathollow dome lling the space between: two carriers. In order to increase the strength of such-I a hollow structure, the two hollow bodies may be4 rigidly united at the adjoining faces asby mortar.l cement, or interlocking by longitudinally disposed: tongue and grooves formed on the adjoining faces," or by rabbeting, overlapping or serrating the adjoining facesand so forth. If a greater distanceI between the carriers is desired, more than two. adjacent hollow bodies may be arranged. between. two adjacent carriers. In this case suchfafselfif,

supporing ceiling formed of the hollow bodies man. 105

engage'in the manner of key stonesVV of an-arch` 110;l

sitlon of the hollow body.

between the two outer hollow bodies and thus support the latter and each other mutually.

Another method of fixing the ferro-concrete hollow ceiling may be effected according to the invention by providing open topped spaces between adjacent hollow bodies of the ceiling and lling such spaces with cement or the like, the latter when hard forming wedges which act in the manner of arch key stones.

Further, the strength of the ceiling may be increased by a special construction of the ferroconcrete carriers, heretofore rendered impossible owing to the small distance between the carriers, this construction consisting in providing the ferro-concrete carriers with a broad foot plate between their points of inflection and supports, said foot plates providing 'the carriersin these sections with a statically correct I shaped section to accord with the negative moments acting at this part. The hollow bodies adjacent the carriers are of course, correspondingly shaped to suit this I shaped profile of thecarriers in these sections.

Obviously in such cases where there is no ob- -jection to the free use of cement, the ferro concrete carriers may be also provided for the whole of ytheir length with such' a plate on their lower extremities that is to say they may be of I section. Several constructional forms of ferro-concrete ceilings according to the invention and their hollow bodies are shown in section longitudinally of the carriers and hollow bodies, and wherein.`

Figs. 1, 6, 8, 9 and 10 show different constructions of.ceilings with only two adjoining hollow f bodies.

Figs. 7, 15 and 16 are similar views of ceilings having'three adjoining hollow bodies.

Figs. 10 and 16 show the particular construction of the ceiling between the points of inflection and the places where their carriers are inserted.

Figs. 2 to 5 and Figs. 11, 12 and 14 show different constructions of hollow bodies for the ceiling, thelatter three figures being shown to ra Fig. 13 shows a cover plate for the lower carrier side for use with the form of ceiling shown in Figs-10 and 16, and

Fig. 17 shows diagrammatically in vertical longitudlnal section one end of a carrier of ceiling.

Referring to the drawings, 1 designates the ferro-concrete carriers of theceiling, and 2a 2b are the hollow bodies adjoiningk said carriers, whilst in Figs. 10, 12 vand 16 the hollow bodies are designated 2A and 2B. 2c designates a third hollow body, which may be introducedbetween these hollow bodies. The hollow bodies which are f advantageously made of clay in the form of prismatic hollow bricks, open at oppositerends, have in all cases a fiat base, whilst the top wall may be of any desired shape, and the sides are inclined, the inclination varying according to the particular arrangement and po- In the case of the hollow bodies 2a,2b or 2A, 2B adjoining the carriers 1, the longitudinal sides adjacent the carriers yare always at an obtuse angle to the base, and their opposite longitudinal sides are at right angles or at an angle less than a right angle to the base; 'the base extends laterally outwards to form a ange '3 von that side adjacent the carriers, the width of this ange being equal to half the width of the' base of the ferro-concrete carrier 1. vThe overall width of the base of a.

the Y hollow body including the iiange is approximately equal to 30 centimeters, which accords with the dimensions of the known separate hollow bodies, so that a pair of hollow bodies 2a and 2b arranged as shown with their ilangeless sides, adjoining forming together a single symmetrical hollow body of twice the width of conventional hollow bodies, with as avresult double the usual distance between the carriers. The two hollow bodies may be connected to form a unitary body by an interlock between their adjoining sides produced as by a tongue and groove joint, as shown in Figs. 1 and 2, or by a stepped engagement according to Figs. 3 and 4, or by a serrated joint as shown in Fig. 5 or other connection. The adjoining side's may .also be smooth (Figs. 6 and 8), in which case'they may be connected by a binding mediumV such as cement mortar. Obviously hollow bodies connected by interengaging means may also be cemented together at the joint. The top side of the hollow bodies may be ilat or otherwise shaped, as for instance, roof shaped, as shown in Fig. 4, or waved according to Fig. 5 and so forth. These bodies may be der' void of division ,walls as shown in Fig. 3, or divisions 4'may be provided as shown'in the other gures, and there may be one or more of such divisions. The shapelof the carriers is determined by the trapezium shaped channels between' the successive adjoining pairs of hollow bodies 2aI and 2b, or 2A and 2B, presenting the inclined side, and such carriers are accordingly of trapezium shape in cross section, that is to say their sides diverge downwards. These inclined sides ofthe vcarriers 1 form the abutment against which bear the vault constituted by the hollow members 2a and 2bor2A and 2B or 2c which ll the space between adjoining carriers. (Figs.fl, 6, 7, 8, 9 and 15.) These carriers 1 are provided at the'bottom with the,v conventional iron reinforcement wires 5, and at the top they present the top plates 1a which take the compression stresses. Obviously these plates la, as shown in` Figs. 9, 10, 15and 16 may be united to form a single continuous plate without departingk from the spirit of the invention. On top of the plates 1a is the usual slag or other filling 6, Fig. l, on whichare placed the beams 8 carrying the flooring boards 7.

Figs. 7, 15 and 16 show constructions which are particularly adapted for ceilings having narrow spans and comparatively small loads, and wherein the distance between the carriers is increased to 'I5 toi 30 centimeters by means of a third hollow body 2c introduced between the pairs of hollow bodies 2a and 2b or 2A and 2B. In this casethe iiangeless side faces of the two hollow bodies 2a and 2b or 2A and 2B are again inclined and diverge upwards, whilst the third hollow body 2c placed between them is'wedge shaped, so that it acts in the manner of a key stone between the two other hollow bodies 2a. and 2b or 2A and 2B. This third body 2c may be lower than the two others, or it may be of the same height as indicated by broken lines in Figs. '7, 15 and 16.r

Further, in lieu of this third hollow body 2c there may be one or more solid bricks.

In all ,constructional forms of such a ceiling comprising hollow bodies the bases of all of them lie in a common plane, so that the underside of the ceiling is not only completely flat but after the bases of the members 1 have been covered by the flanges 3 ofthe hollow bodies, or as shown in Figs. 10 and 16, by a cover plate 1l of the same material, the ceiling is composed throughout of the same material, i. e. brick, so that the coat of plaster on the underside cannot possibly develop flaws or cracks as a result of temperature fluctuations.

For the sake of completeness there is shown in Fig. 8 a construction of ceiling which may be considered of secondary importance in view of its greater weight and cost of production, and wherein the hollow bodies 2a and 2b and the carriers are made of concrete. vIn this case ilanges 3 of the hollow bodies of clay for covering the ferro-concrete carriers are dispensed with, and in lieu thereof there are provided boards 9 for closing the channels between the several rows of hollow bodies, and the hollow bodies have to be laid with the aid of templets or by measuring.

Figs. 9 and 10 and 15 and 16 show constructions of ceilings in which there are spaces 10 between the adjacent hollow bodies, these spaces being closed at the bottom and open at the top, and which are lled inwith concrete or mortar during the building of the ceiling, this filling when hard, forming keys disposed between the hollow bodies and acting in the manner of key stonesin an arc. These spaces 10 may be produced either by providing the opposite longitudinal sides of adjacent hollow bodies 2a, 2b or- 2A, 2B with inclinations directed in opposite directions, (Figs. 9 to 12), or the lower edge of one or both of complementary longitudinal sides of the hollow bodies are provided with a narrow longitudinal rib 3a which separates the hollow bodies, as shown `applied to the centre body 2c in Figs. 14 to. 16. In both cases the adjoining bodies are thus only able to touch along the lower longitudinal edges (Figs. 9-12 and Figs. 15 and 16), a space 10 being left at the top which, in the rstcase, tapers outwards towards the top, (Figs. 9-12) and in the second case the space is of equal width from top to bottom and is determined vby the width of the lower rib or ribs 3a. v

Figs. 10, 12, 16 and 17 relate to constructions of ceilings in which the fastening of the hollow bodies is effected by the particular construction of their carriers, that is to say, by the hollow bodies adjoining the carriers in the sections to the right of :zt-:r between the points of inflection and the supports for the carriers (Fig. 17).

In these sections, where only negative moments occur, so that the lower parts of the carriers are subjected to compression strains and the upper to tensile strains, the lower part of the carriers are so dimensioned as Vto accord with the compression strains occurring at this part, the foot plate 1b being broadened so that the carriers are of substantially I section in these sections (Figs. 10 and 16).

Obviously the reinforcement wire 5 is displaced from the point of inection to the upper carrier part in accordance with the tensile strains occurring in the upper part of the carrier, as shown to the right of :zt-zr, Fig. 9.

The hollow bodies 2A and 2B adjoining the carriers in this section are so formed in accordance with this I section that the lower part of the longitudinal sides adjoining the carriers, together with the lower flange 3 engaging under the carrier, is set back to the extent of approximately -half the width of the hollow body (Fig. 12), so that a recess A is formed on these sides of the bodies in which the foot plate 1b of the carrier engages.

Between the points of inflection of the carriers (to the left of .7J-a: in Fig. 17) where there are only negative moments, the carriers may be constructed in the manner previously described, where they are provided in any case with suitable head plates la to take the compression strains occurring in the upper part of thev carrier, these head plates giving the carriers an I section, while the tensile strains occurring in the lower part of the carrier are taken vby the iron reinforcements 5 arranged at this part. 90

Where the quantity of cement used is of no consequence, the carriers may be of I section throughout their length along the lower belt, in order to simplify the production of the ceiling.

With this I shaped section of the lower part v ofy the carriers the set back ilanges 3 of the hollow bodies 2A and 2B do not. completely engage under the now broadened base of the carrier 1, a space is left between pairs of flanges 3 which is lled in with a. plate 11 (Fig. 13) 100 so that the uniformity'of the material brick forming the face of the ceiling is preserved, this plate also serving as a. lower cover fory the production of the carrier 1. This plate 11 is supported by the inclined ends of the anges 3 of the hollow bodies 2A and 2B as shown in Figs. 10 and 16.

It may be iinally remarked that in order to ensure the concrete or plaster adhering firmly to the hollow bodies 2a, 2b, and 2A, 2B, as well110 as to the cover plates 11, the hollow bodies and plates are preferably provided on their appropriate faces with straight or dove-tailed longitudinal grooves 12, as shown in Figs. 11 to 14.

What I claim is:

1. A ceiling construction, comprising ferro.- concrete carriers, and a plurality of hollow bodies interposed between adjacent carriers in series at right angles to their longitudinal run, the lower portions of said carriers being of I section.

2. A ceiling construction, comprising ferroconcrete carriers, and a plurality of hollow bodies interposed between adjacent carriers in series at right angles to their longitudinal run, the lower portions of said carriers being of I section between their points of inection and their supports.

3. A ceiling construction, comprising ferroconcrete carriers, and a plurality of hollow bodies interposed between adjacent carriers in series at right angles to their longitudinal run, the lower portions of said carriers being of.I section, the longitudinal sidewalls of the bodies adjoining the carriers being set back at their lower portions to correspond with the lower portions of the carriers.

4..A ceiling construction, comprising ferroconcrete carriers, and a plurality of hollow bodies interposed between adjacenty carriers in series at right angles to their longitudinal run, the bases 1.10 of the hollow bodies being extended laterally beyond the sides adjacent to the carriers thereby to form a ange in engagement with the underside of the carriers.

LADISLAUS NAVRATIL. 

